Furnace



March 25, 1930. R. s. MCNANEY f 1,751,829

y FURNAGE Filed oct. 22, 1928 2 sheets-sheet 1 ATTORNEYS March 25,` 1930.

R. S. MQNANEY FURNACE 2 Sheets-Sheet 2 Filed` Oct. 22, 1928 u nlll-In-mio WMM im w in W 'I ISIHH INVENTOR M727 ATTORNEY-Sl Vlll/4714141115 Patented Mar. 25, 1930 c i i UNITI-:D STATES P'ATENroFFlcE RALPH' 8. yMCIEI'AIN'E'Y, 0l' DOWAGIAC, MICH GAN ABSIGNOR T0 DOWAGIAC STEEL FUR- Nacn COMPANY, or nowneuc, me GaN, A coaronarioN or MICHIGAN rUnNacn applicati@ med october aa, 192s. serial Na. 314,209.

The invention relates to warm airfurnaces adapted forlboth gaseous liquid or solid fuel.

The primary object of the invention is to v provide a construction which is as-t-ight throughout, thereby insuring that t e products of combustion are confined within/the chamber and iiue passageways and are not vpermitted to escape into the casing area or into the furnace room.

' metal parts joined together in such a manner' as to insure gas-tight joints under all conditions of operation. Another object is to construct the parts in such a manner as to render the combustion chamber and flue passageways subtsantiall seamless.

These an other objects are attained in the improved furnace construction hereinafter more fully described and illustrated in the accompanylng drawings, wherein' Figure 1 is a central longitudinal section through the improved furnace; r Y Figure 2 is an elevation of the furnace with the outer casing removed showing the main drum and the radiator Figure 3 is an axial section through the damper operating mechanism;

Figure 4 is a section on the line 4-4 of v Figure 3; j Figure 5 1s an enlarged view ofthe welded icult -to always maintain a gas-tight seal for diierences in expansion of the parts will frernace construction substantially all of the adjacent sections are secured together by welding thereby permanently mtegratm the same. 'Ihe furnace is` constructed of oth 5 sheet metal and cast metal parts, the latter be- -Another obj ect is to provide a composite construction having both sheet metal and cast:

gently open the joints. In 'my improved ing used where it is particularly desirable, either because of the requirement for rigidity or because the desi of the parts is more readily obtained by t e use of castrather than 4sheet metal. Where the lcast metal parts are joined to the sheet metal parts I vhave provided such materials as can be permanently welded together lin order to maintain tight. `oints, an I have therefore used materials aving substantially the same coeiiicient of expansion. More specifically, I have provided a construction using sheet steel and cast steel since these two materials, have substantially the same coefficient of expansion and can be weldedtogether to form an integral structure having a gas-tight joint. The use of cast steel for the castingv sections adjacent the sheet metal sections mstead of the use of the more common material, cast iron, makes'a far better construction for it eliminates the necessity of calking the joints between the cast and sheet metal `parts with putty or other use of bolts, rivets, screws and the like and .also eliminates joints between materials of unequal coefficient of expansion and substitutes for the above a strong, durable leakproof and substantially seamless housing for the combustioin gases. f 1 In detail, 10 is a cylindrical drum prefersoV equivalent substances and it eliminates the ably formed of heavy sheet steel and having? at its upper end -a dome-shaped head 11 witli* A a flange 12 telescopically engaging the drum. ""7

Head 11 is electrically welded to the top end i of drum `10 at the shoulder of fiange 12 asindicated at 13 and there is also another feld 14 between the lower end of iange 12 and the inside portion 'of drum 10, thus making a double welded jointrfor the full circumferl ential distancebetweendrum 10 and head 11. 15 is a fire door extension of the drum 10 which also is preferably formed of sheet steel having it'sinner end weldedk at 16 to the drum. At'the outer end of this extension 15 is a cast steel door frame 17 having a flange-18 overlapping the member 1 5 and with its end welded to said member as indicated at 75. Thus, lthe cast metal door frame 17 is united to the sheet metal extension of the drum in a permai nent manner, free lfrom any joint where leakl' age might occur and this is made possible because the frame is made of cast steel which has the same coefficient of expansion as sheet steel and is capable of being successfully weloed thereto. The sheet metal extension 15 is protected b a cast iron liner 19 inserted therein and liaving at its inner end a fiange 2U for protecting the welded joint between the member 15 and the member 10. A similar liner 21 is arranged on the bottom of extension 15 with a flange 22 extending over the ed e of fire brick lining 54.

n the rear of the drum 10 is a radiator 23 spaced from and detachably connected to the drum 10. The radiator isin the form of a segmental drum, partially surroundingY the main drum 10. In order to maintain a gastight joint between the main drum and the radiator, it is preferable to have only one point of separation between the two units and have the remaining sections permanently joined together by welding. It is also desirable that the parts joining the drum and radiator have rigidity so as to maintain their shape and form and for these and other reasons I have found it advantageous to use two4 connecting collars 24 and 25 made of steel castings. The collar 24 projects from the radiator 23 and is integrally united thereto by welding at the point 26. Similarly the collar 25 projects from the drum .10 and is welded thereto at the point 27. The two collars telesco ically engage each other, one having the ange 28 engaging an annular recess 29 in the other and each being provided with outwardly extending anges 30 secured together by bolts 31. The caststeel collars are protected throughout theirentire .length by a cylindrical liner 32 formed preferably of cast iron and having an outwardlyextend-k ing flange 33 protecting the welded joint27 between the drum 10 and the collar 25.- The liner is secured in position by a set-screw 34.

The radiator 23 is formed of sheet steel and consists of a segmental body portion 35 and upper and lower heads 36 and 37 which are welded to the body. The smoke flue 38 and the clean-out flue- 39 are formed by sheet.

steel extensions welded to the body 35. W'ithin the radiator 23 is a baile or deflector plate 40 arranged in aninclined position to .extend from a point closely adjacent the inner wall and near the lower end of the radiatorto the top of the radiator near the middle thereof. The baiiie 40 is. also a curved section so that its opposite edges are adjacent to the outer wall of the drum, thereby causing the gaseous products which pass from the drum 10 into-the radiator 23 to be deflected to the opposite sides thereof and downward and then upward through the centerl of the drum to the escape flue 38. To permit of direct draft when firing the furnace and thereby prevent the products of combustion vfrom es- ,capin'g yinto' the basement area through the feed door, there is a dam er 41 located in an` opening in the ba e which is in alignment with the nip le or collar 24 and flue 38. This damper 1s hinged at 42 and is weighted so as to automatlcally close by gravity. In case of a sudden explosion of combustible gases in the drum 10, the damper 41 can automatically swing open and allow the gases to pass directly into and through flue 38, rather than pursue their regular course downwardy and then upward around baie 40 with a possibility of blowing open door on clean-out 39 and distributing soot, smoke and ashes in basement area. To open the damper 41 mechanically there is provided a vertical rock shaft 43 having an arm 44 adapted to bear against the damper at a point below its hinge pivots 42. Located on the rock shaft 43 and electrically welded thereto is a flat steel washer 43a whichseals the opening in a bearing 45 where rock shaft 43 enters, to prevent the products kof combustion from finding their way out into the casing arca. The bearing 45 in whichthe rock shaft is j ournaled is preferably formed of cast steel in order that it may be welded to the sheet steel radiator and thus make a tight joint. The bearing 45 has a Hange 46, the underside of which is welded to the head 36 of the radiator. The top face of the fiange has a series of raised rings 47 with annular recesses 48 therebetween into which is fitted a complementary part 49 witha series ofrings 50 arranged in the recesses 48. The part 47 is fixed to the rock shaft 43 by a set screw 51 and is provided with a lever 52 for actuating the rock shaft and adjusting the damper. A rod 53 extends from the lever to the front ofthe furnace and provides a convenient handle for opening the damper before opening the lire door. While the bearing 45 is of cast steel, the cooperating part 47 is preferably of cast lron since it does not require welding. Leakage through the damper operating means is e ectively prevented by reason of the large number of bearing surfaces formed` by the concentric rings 47 and 50 andiby the close contact of the bearing member 45 and the washer 43a.

The refractory lining for the portion ofv `of any suitable construction as indicated at 54 and may be supported on a ring 21 secured within the drum 10, such ring and supports being removable so as to allow lowering the refractory lining to the bottom of the drum 10 at plate 55 forming a lining for oil burners located in the ash pit and extending inward through the ash pit opening. Where solid fuel is used there is provided a grate 56 of any suitable construction or where gas or oil fuel is used any suitable equipment may be installed in place of this grate.

The drum 10 and radiator 35 are surrounded by sheet metal `air jacket 57, which at its lower -end engages a supporting ring 58 attached in the middle and at the back of drum 10 and at the bottom and on each side of cast metal member 55.4 At thefrontofthe furnace there are two cast metal members 59 and 60, which extend from the base to a point above the fire door. At the upper end of member 59 there is a water tank or pan 61 The lower end of member 60 forms the door frame for the ash door 7 2. These members 59 and 60 are bolted together at a point.. directly below the cast steel door frame 17, lower member 60 being bolted to the ash pit section and upper member 59 to the cast steel door frame 17, forming a yieldable connection to allow for the expansion and contraction of the members. The member 60 has a bead 62 extending around the door frame 17 and the bolts 63 which connect the members-62 and 17 pass through this bead. Thus there is a portion of the bolt extending through the hollow of the bead which is suliiciently flexible to compensate for the different expansions in the members 17 and 59 and 60, and also drum 10.

The construction described permits of detaching the drum 10 from 'radiator 35 for convenience in shipment. When the furnace is assembled, the radiator 35 is coupled to the drum 10 by engaging the collars y2li and 25 with each other, wrapping a piece of pure asbestos rope between the flanges of the two parts and bolting together with the bolts outside of the asbestos rope. The outer sheet metal jacket 57 may then be put in place and secured in the usual manner. The liners 19 formed of cast steel and a welded joint beditional members formed of cast steel welded j and unriveted to said drum.

6. In a warm air furnace, a sheet steel drum forming the body portion of the furnace and having a door opening therein, a cast steel door frame surrounding said opening and a welded joint between said cast steel door frame and sheet steel drum.

7. In a Warm air furnace, a body portion formed of sheet steel and having welded joints and a door frame of substantially heavier section than said sheet steel, said door frame forming a reinforcement for imparting rigidity to said sheet steel structure at the door opening and being composed of a steel casting and a Welded j oint between said cast steel door frame and sheet steel body.

8. In a warm air furnace, a body portion formed of sheet steel -having a door o ening therein, a cast steel door` frame having anges extending `transversely to the surface of said body portion, said Aflanges being welded to said drum forming a gas tight joint and a cast iron lining within said door frame having a flange overlapping the marginal portion of said sheet metal door opening and protecting the said weld from combustion gases within said body ortion.

In testimony w ereof I aliix my signature.

RALPH S. MONANEY.

and 32 are`placed in their respective posil tions to protect the casing around the fire door openin and the escape fiue for the hot gaseous pro ucts of combustion.

In operation, the gases both before and after combustion are prevented from passing out into the air jacket either from the drum 10, the radiator 35, or any of the connectin parts. This is because all of the joints which are exposed to such gases have been electrically arc welded, thus forming a gas-tight seal and making the product potentially seamless.

What I claim as my invention is:

1. In a furnace, a caslng formed of adjacent sheet metal and cast metal sections having welded joints therebetween.

. 2. In a furnace, the combination with a drum formed of sheet metal, of a door frame formed of cast metal and a welded joint bef tween said door frame and drum.

3. In a furnace, the combination of a drum formed of sheet metal parts having the joints therebetween Welded and one or more cast metal members Welded to the said drum to impart rigidity thereto and to form a gastight seal.

4. In a furnace, the combination with ay drum. formed of sheet steel, a door frame 

